It reportedly remains unclear whether Jacobson -- who worked with Zoe for the past four years and appeared on both two seasons of Zoe's The Rachel Zoe Project Bravo reality series -- was fired or quit.

While sources told People that Jacobson was fired Friday morning effective immediately, Jacobson sent an email to her contacts in which she claims it was her decision to leave.

"After four amazing years at Rachel Zoe Corporation, I'm saddened and exhilarated at the same time to announce my departure," reads the email, which was obtained by Fashionista.com.

"After much thought and consideration, I have decided to take the challenging leap to go off and style on my own."

Jacobson also announced her departure in a Thursday posting to her Twitter account.

"Today is an end of an era and a beginning of a new professional chapter. Looking forward to what the future brings...!!!" she wrote.

The Rachel Zoe Project'ssecond season had repeatedly shown Jacobson clashing with Brad Goreski, Zoe's other styling assistant, and expressing frustration about her stagnant role in the celebrity stylist's business and considering leaving.

The season finale, which aired last month, had featured Zoe promoting Jacobson to a new head of product development position.